The Kentucky Derby takes place every year on its traditional date of the first Saturday in May. This is a race that many people follow and try to handicap even if theyre not typically horse racing enthusiasts. Understanding race horses is hard work, and a discipline unto itself.

Despite the complexity of understanding horse racing, there are a few basic rules that can help the novice watch the Kentucky Derby with a greater degree of enjoyment. Until recently, the Derby was a race dominated by the favorite. In the 1970’s great horses like Secretariat and Seattle Slew blew away the field but since Spectacular Bid’s winning run in 1979 there have been only a couple of favorites to win the big race. While a serious horse player might not want to categorically dismiss the popular favorite, for the horse racing novice this is a helpful way to narrow down the field.

In all fairness, it should be noted that the favorite has been a historically strong proposition. In the 135 Kentucky Derby races the post time favorite has placed in the money at a 69% clip over the history of the race. So why have the favorites been on such a money losing run in the past two decades? My personal theory is that it is a function of the growing hype surrounding the race”in other words, you get a lot of amateur horse racing fans that distort the notion of the favorite being the most likely to win the race. The most hyped horse becomes the favorite, but this is not always the best horse. In any case, though it could be argued that the anti-favorite bias could be due for a turnaround, for the purpose of understanding this particular race Im going to forget about the post time favorite.

Post position is also something that the horse racing neophyte should pay attention to. Obviously post position number 1 is an advantage relative to the outer ones, but it hasnt been a strong edge over the other inside positions. Twelve Derby winners have had the #1 position going into the race (the most of any position) but positions #4 and #5 have had ten winners each. In terms of percentages, positions #1 through #5 have yielded 49 winners (or just under 40%). On the other hand, the outermost positions (#11 through #20) have had just 16 winners (or just under 13%). It is important to note that theres not always that many horses in the race, which would obviously result in few higher posts winning. Still, concentrating on horses with favorable post positions is another way to pare down a field that you know little about.

Another factor worthy of consideration is the horses lineage and breeding. Start at the beginning”where the horse was born. Most, but not all, serious racehorses are born in Kentucky. If you see a horse in the race that wasnt, forget them. This is not any sort of home field advantage but a result of the concentration of the Thoroughbred horse industry in the state. Over 80% of Kentucky Derby winners have been born in Kentucky. Next, consider the horses gender, or more specifically dont consider any entry with a gender other than male. Only eleven horses other than intact males have ever won the race (eight geldings and three fillies). A gelding did win as recently as 2003, when Funny Cide took the roses but again for the newcomer this is an easy way to cut down the horses under consideration. This isnt a gender bias or anything, but for our purposes we can forget about non-male horses.

Don’t forget to consider dosage index numbers. These are a complex mathematical formula that measures a horse’s breeding lineage plus his past performance. You want to look for horses with a dosage index of 4.00 or less–over half of Derby winners have met this criteria since dosage numbers came into common usage in the mid 1980’s.

If you want to learn about horse racing in more depth, there are countless books available to introduce you to the subject. For a recreational fan who just wants to have a better understanding of the Kentucky Derby, these rules can help.